Association of orthostatic hypotension with incident dementia, stroke, and cognitive decline

Blood pressure and the brain: the conundrum of hypertension and dementia

As the population ages, the anticipated rates of dementia worldwide are likely to increase dramatically, especially in low- and middle-income countries; thus, any opportunity to modify dementia risk is especially critical. Hypertension is one risk factor that is highly prevalent, consistently important for late-life brain health, and which could represent a target for prevention of dementia. Furthermore, hypertension is the most significant modifiable risk factor for stroke. This review will summarize existing literature linking hypertension with dementia and brain health more broadly, will discuss potential mechanisms linking hypertension with brain health, and will consider specific factors that may impact not only the relationship between hypertension and the brain but also the importance of treatment, including different associations over the life course.

Meta-analysis of heat-induced changes in cardiac function from over 400 laboratory-based heat exposure studies

Heat waves are associated with increased fatalities from adverse cardiovascular events attributed to the negative effects of heat on cardiac function. However, scientific understanding of acute cardiac adjustments to heat has come primarily from laboratory experiments employing insulated and encapsulated heating modalities, most commonly water-perfused suits. We evaluated whether findings from those studies reflect cardiac responses during more natural exposures to hot ambient conditions simulated in climate-controlled chambers by synthesizing the findings from over 400 laboratory-based heat exposure studies (6858 participant-exposures) published between 1961-2024. Among all included studies, median (interquartile range) elevations in core temperature and heart rate from baseline to end-exposure were 0.9 (0.5-1.3)°C and 27 (15-40) beats/min. Multilevel mixed-effects meta-analyses revealed exacerbated elevations in heart rate, cardiac output, and rate pressure product (estimate of cardiac workload) and blunted falls in systolic pressure in participants heated via encapsulated modalities. Leveraging the large dataset, we also provide empirical estimates of body temperature and cardiovascular responses to a wide range of conditions experienced during heat waves. With rising global temperatures, ecologically-minded physiological research is needed to improve understanding of the effects of heat stress on cardiac responses and further the development of robust climate health models and evidence-based heat-health guidance.

Hypotension with neurovascular changes and cognitive dysfunction: An epidemiological, pathobiological, and treatment review

ABSTRACT

Hypotension is a leading cause of age-related cognitive impairment. The available literature evidences that vascular factors are associated with dementia and that hypotension alters cerebral perfusion flow and can aggravate the neurodegeneration of Alzheimer's disease (AD). Despite the discovery of biomarkers and the recent progress made in neurovascular biology, epidemiology, and brain imaging, some key issues remain largely unresolved: the potential mechanisms underlying the neural deterioration observed in AD, the effect of cerebrovascular alterations on cognitive deficits, and the positive effects of hypotension treatment on cognition. Therefore, further well-designed studies are needed to unravel the potential association between hypotension and cognitive dysfunction and reveal the potential benefits of hypotension treatment for AD patients. Here, we review the current epidemiological, pathobiological, and treatment-related literature on neurovascular changes and hypotension-related cognitive dysfunction and highlight the unsettled but imminent issues that warrant future research endeavors.

Hypertension and orthostatic hypotension in the elderly: a challenging balance

Hypertension and orthostatic hypotension (OH) frequently coexist in the older population, both stemming from impaired blood pressure (BP) regulation. Managing hypertension in patients with OH presents a significant clinical challenge, particularly in frail older adults who are also prone to falls. Hypertension treatment is often suboptimal in this population due to concerns over the potential increased risk of falls associated with treatment. However, current clinical guidelines provide limited guidance on managing this complex issue. This review explores the pathophysiology of hypertension and OH, reviews existing guidelines, and examines the evidence surrounding hypertension management in patients with OH. Additionally, we provide an overview of research focused on frail older adults and offer expert-opinion-based recommendations for the management of hypertension and OH in routine clinical practice.

Physiological Targets for Orthostatic Hypotension: Improving Nonpharmacological Interventions in Patients with Orthostatic Cerebral Hypoperfusion

Orthostatic hypotension (OH) is a form of orthostatic intolerance (OI) and a key physiological indicator of autonomic dysfunction that is associated with an increased risk of major cerebrocardiovascular events. Symptoms of cerebral hypoperfusion have been reported in patients with OH, which worsens symptoms and increases the risk of syncope. Since pharmacological interventions increase blood pressure (BP) independent of posture and do not restore normal baroreflex control, nonpharmacological treatments are considered the foundation of OH management. While reductions in cerebral blood flow velocity (CBFv) during orthostatic stress are associated with a decrease in end-tidal CO2 (EtCO2) and hypocapnia in patients with OI, their contribution to the severity of OH is not well understood. These measures have been physiological targets in a wide variety of biofeedback interventions. This study explored the relationship between cardiovascular autonomic control, EtCO2 and cerebral hypoperfusion in patients (N = 72) referred for OI. Patients with systolic OH were more likely to be male, older, demonstrate reduced adrenal and vagal baroreflex sensitivity, and reduced cardiovagal control during head-up tilt (HUT) than patients without systolic OH. Greater reduction in CBFv during HUT was associated with a larger reduction in ETCO2 and systolic BP during HUT. While deficits in cardiovascular autonomic control played a more important role in systolic OH, reduced EtCO2 was a major contributor to orthostatic cerebral hypoperfusion. These findings suggest that biofeedback treatments targeting both the autonomic nervous system and EtCO2 should be part of nonpharmacological interventions complementing the standard of care in OH patients with symptoms of cerebral hypoperfusion.

Magnesium and Cognitive Health in Adults: A Systematic Review and Meta-Analysis

Magnesium (Mg) plays a key role in neurological functioning and manifestations. However, the evidence from randomized controlled trials (RCTs) and cohorts on Mg and cognitive health among adults has not been systematically reviewed. We aimed to examine the associations of various Mg forms (supplements, dietary intake, and biomarkers) with cognitive outcomes by summarizing evidence from RCTs and cohorts. PubMed, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials were searched for relevant peer-reviewed articles published up to May 3, 2024. Three random-effects models were performed, when appropriate, to evaluate the relationship between Mg and cognitive outcomes: 1) linear meta-regression, 2) nonlinear (quadratic) meta-regression, and 3) meta-analysis using Mg variables categorized based on pre-existing recommendations. Three RCTs and 12 cohort studies were included in this systematic review. Evidence from the limited number of RCTs was insufficient to draw conclusions on the effects of Mg supplements. Cohort studies showed inconsistent dose-response relationships between dietary Mg and cognitive disorders, with high heterogeneity across populations. However, consistent U-shape associations of serum Mg with all-cause dementia and cognitive impairment were found in cohorts, suggesting an optimal serum Mg concentration of ∼0.85 mmol/L. This nonlinear association was detected in meta-regression (Pquadratic = 0.003) and in meta-analysis based on the reference interval of serum Mg (0.75-0.95 mmol/L) [<0.75 compared with 0.85 mmol/L: pooled hazard ratio (HR) = 1.43; 95% confidence interval (CI) = 1.05, 1.93; >0.95 compared with 0.85 mmol/L: pooled HR = 1.30; 95% CI = 1.03, 1.64]. More evidence from RCTs and cohorts is warranted. Future cohort studies should evaluate various Mg biomarkers and collect repeated measurements of Mg intake over time, considering different sources (diet or supplements) and factors affecting absorption (for example, calcium-to-Mg intake ratio). This systematic review was preregistered in PROSPERO (CRD42023423663).

Orthostatic hypotension and cognitive impairment: Systematic review and meta-analysis of longitudinal studies

The association between cognitive disorders and orthostatic hypotension (OH) has been empirically explored, but the results have been divergent, casting doubt on the presence and direction of the association. The objective of this meta-analysis was to systematically review and quantitatively synthesize the association of OH and cognitive function, specifically mean score on the Mini-Mental State Examination (MMSE), cognitive impairment and incident dementia. A Medline search was conducted in May 2022 with no date limit, using the MeSH terms "orthostatic hypotension" OR "orthostatic intolerance" OR "hypotension" combined with the Mesh terms "cognitive dysfunction" OR "Alzheimer disease" OR "dementia" OR "cognition disorder" OR "neurocognitive disorder" OR "cognition" OR "neuropsychological test". Of the 746 selected studies, 15 longitudinal studies met the selection criteria, of which i) 5 studies were eligible for meta-analysis of mean MMSE score comparison, ii) 5 studies for the association of OH and cognitive impairment, and iii) 6 studies for the association between OH and incident dementia. The pooled effect size in fixed-effects meta-analysis was: i) -0.25 (-0.42; -0.07) for the mean MMSE score, which indicates that the MMSE score was lower for those with OH; ii) OR (95 % CI) = 1.278 (1.162; 1.405), P < 0.0001, indicating a 28 % greater risk of cognitive impairment for those with OH at baseline; and iii) HR (95 % CI) = 1.267 (1.156; 1.388), P < 0.0001, indicating a 27 % greater risk of incident dementia for those with OH at baseline. Patients with OH had a lower MMSE score and higher risk of cognitive impairment and incident dementia in this meta-analysis of longitudinal studies. This study confirmed the presence of an association between OH and cognitive disorders in older adults.

Longitudinal prevalence of neurogenic orthostatic hypotension in the idiopathic Parkinson Progression Marker Initiative (PPMI) cohort

BACKGROUND

Reported orthostatic hypotension (OH) prevalence in Parkinson's disease (PD) varies widely, with few studies evaluating specifically neurogenic-OH (nOH). The ratio of orthostatic heart rate (HR) to systolic blood pressure (SBP) change (Δ) is a valid screening method to stratify nOH/non-nOH but has had minimal epidemiologic application.

OBJECTIVE

To estimate the prevalence of nOH and non-nOH in the PPMI using the ΔHR/ΔSBP ratio and examine associations between nOH and various motor and non-motor measures.

METHODS

Longitudinal orthostatic vitals and motor and non-motor measures were extracted (baseline-month 48). Patients were consensus criteria classified as OH+/-, with ΔHR/ΔSBP sub-classification to nOH (ΔHR/ΔSBP < 0.5) or non-nOH (ratio ≥ 0.5). Prevalence was determined across visits. Independent linear mixed models tested associations between nOH/non-nOH and clinical variables.

RESULTS

Of N = 907 PD with baseline orthostatic vitals, 3.9 % and 1.8 % exhibited nOH and non-nOH, respectively. Prevalence of nOH/non-nOH increased yearly (P = 0.012, chi-square), though with modest magnitude (baseline: 5.6 % [95 % CI: 4.3-7.3 %]; month 48: 8.6 % [6.4-11.5 %]). nOH patients were older than PD with no OH and nOH was associated with greater impairment of motor and independent functioning than non-nOH/OH- groups. Cognitive function and typical OH symptoms were worse in PD + OH, generally.

CONCLUSIONS

nOH prevalence was greater than non-nOH in the PPMI early PD cohort, with modest prevalence increase over time. Our findings are consistent with prior studies of large cohorts that evaluated nOH, specifically. Those with early PD and nOH were likelier to be older and suffer from greater motor and functional impairment, but OH presence was generally associated with more cognitive impairment.

Orthostatic Hypotension Promotes the Progression From Mild Cognitive Impairment to Dementia in Type 2 Diabetes Mellitus

CONTEXT

In type 2 diabetes mellitus (T2DM), orthostatic hypotension (OH) is associated with cognition, but the mechanisms governing the link between OH and cognition are still unclear.

OBJECTIVE

We sought to analyze Alzheimer's disease (AD) biomarkers and the part of complement proteins in modulating the association of OH with cognitive impairment and examine whether OH could accelerate the clinical progression of mild cognitive impairment (MCI) to dementia in T2DM.

METHODS

We recruited patients with T2DM with MCI and collected general healthy information and blood samples. Complement proteins of astrocyte-derived exosomes were isolated and AD biomarkers of neuronal cell-derived exosomes isolated were quantified by enzyme-linked immunosorbent assay. Cognitive assessments were performed at patient enrollment and follow-up.

RESULTS

Mediation analysis showed that the influence of OH on cognition in T2DM was partly mediated by baseline AD biomarkers and complement proteins. Cox proportional-hazards regression proved the OH group had a higher risk of developing dementia compared to the T2DM without OH group.

CONCLUSION

In T2DM with MCI patients, AD biomarkers and complement proteins mediate the effects of OH on cognitive impairment and OH may be a risk factor of progression from MCI to dementia in T2DM.

Associations of Orthostatic Hypotension and Frailty With Dementia and Mortality in Older Adults: A Population-Based Cohort Study

BACKGROUND

This study aimed to assess the associations of orthostatic hypotension (OH), in the presence or absence of frailty, with dementia and mortality in older adults.

METHODS

We conducted a 15-year population-based cohort study including 2 703 baseline dementia-free individuals from the Swedish National Study on Aging and Care in Kungsholmen. At baseline, OH was defined as a decline in systolic/diastolic blood pressure ≥20/10 mm Hg 1 minute after standing up from a supine position. Frailty status was defined following Fried's frailty phenotype. Dementia was diagnosed following the Diagnostic and Statistical Manual of Mental Disorders-fourth edition criteria. Multistate flexible parametric survival models were used to estimate associations of OH and frailty with dementia and mortality.

RESULTS

Robust people with OH (adjusted hazard ratio [HR] = 2.28; 95% confidence interval [CI] = 1.47-3.54) and frail people without OH (HR = 1.98; 95% CI = 1.40-2.82) or with OH (HR = 2.73; 95% CI = 1.82-4.10) had a higher dementia risk than OH-free and robust people. Moreover, frail people, independently of the presence of OH, had higher mortality rate than OH-free and robust people. In individuals who developed dementia during the follow-up period, neither OH nor frailty was significantly associated with mortality.

CONCLUSIONS

Older adults with OH, whether robust or frail, may have a higher dementia risk than those without OH. Older adults with OH, when having frailty, may have a higher mortality rate than those without OH. The concurrent assessments of OH and frailty may provide prognostic values in terms of dementia and mortality risk in older adults.

Orthostatic blood pressure changes do not influence cognitive outcomes following intensive blood pressure control

BACKGROUND

Effects of intensive blood pressure (BP) control on cognitive outcomes in patients with excess orthostatic BP changes are unclear. We aimed to evaluate whether orthostatic BP changes modified the effects of BP intervention on cognitive impairment.

METHODS

We analyzed 8547 participants from the Systolic Blood Pressure Intervention Trial Memory and cognition IN Decreased Hypertension. Associations between orthostatic BP changes and incident cognitive outcomes were evaluated by restricted cubic spline curves based on Cox models. The interactions between orthostatic BP changes and intensive BP intervention were assessed.

RESULTS

The U-shaped associations were observed between baseline orthostatic systolic BP changes and cognitive outcomes. However, there were insignificant interactions between either change in orthostatic systolic BP (P for interaction = 0.81) or diastolic BP (P for interaction = 0.32) and intensive BP intervention for the composite outcome of probable dementia or mild cognitive impairment (MCI). The hazard ratio of intensive versus standard target for the composite cognitive outcome was 0.82 (95% CI 0.50-1.35) in those with an orthostatic systolic BP reduction of >20 mmHg and 0.41 (95% CI 0.21-0.80) in those with an orthostatic systolic BP increase of >20 mmHg. Results were similar for probable dementia and MCI. The annual changes in global cerebral blood flow (P for interaction = 0.86) consistently favored intensive BP treatment across orthostatic systolic BP changes.

CONCLUSION

Intensive BP control did not have a deteriorating effect on cognitive outcomes among hypertensive patients experiencing significant postural BP changes.

Orthostatic Hypotension in Adults With Hypertension: A Scientific Statement From the American Heart Association

Although orthostatic hypotension (OH) has long been recognized as a manifestation of autonomic dysfunction, a growing body of literature has identified OH as a common comorbidity of hypertension. This connection is complex, related to pathophysiology in blood pressure regulation and the manner by which OH is derived as the difference between 2 blood pressure measurements. While traditional therapeutic approaches to OH among patients with neurodegenerative disorders focus on increasing upright blood pressure to prevent cerebral hypoperfusion, the management of OH among patients with hypertension is more nuanced; resting hypertension is itself associated with adverse outcomes among these patients. Although there is substantial evidence that intensive blood pressure treatment does not cause OH in the majority of patients with essential hypertension, some classes of antihypertensive agents may unmask OH in patients with an underlying autonomic impairment. Practical steps to manage OH among adults with hypertension start with (1) a thorough characterization of its patterns, triggers, and cause; (2) review and removal of aggravating factors (often pharmacological agents not related to hypertension treatment); (3) optimization of an antihypertensive regimen; and (4) adoption of a tailored treatment strategy that avoids exacerbating hypertension. These strategies include countermaneuvers and short-acting vasoactive agents (midodrine, droxidopa). Ultimately, further research is needed on the epidemiology of OH, the impact of hypertension treatment on OH, approaches to the screening and diagnosis of OH, and OH treatment among adults with hypertension to improve the care of these patients and their complex blood pressure pathophysiology.

Orthostatic hypotension in stroke/TIA patients: Association with new events and the effect of the NAILED intervention

BACKGROUND

Fear of orthostatic hypotension (OH) and a reported association with an increased risk of cardiovascular (CV) events may limit antihypertensive treatment after stroke/TIA. In the NAILED trial, systematic titration of antihypertensive treatment resulted in lower blood pressure (BP) and reduced the incidence of stroke. Our aim was to assess the association between OH and CV events or death in a stroke/TIA population and the association between group allocation in the NAILED trial and risk of OH during follow-up.

METHODS AND FINDINGS

This post-hoc analysis included all patients with complete BP measurement at baseline in the NAILED trial (n = 814). OH was defined as a drop in systolic BP ≥20 or diastolic BP ≥10 mmHg 1 minute after standing from a seated position. The association between OH and a composite of stroke, myocardial infarction, or death was assessed using an adjusted Cox regression model with OH as a time-varying variable. The association between group allocation (intervention vs. control) and OH was assessed using logistic regression. During a mean follow-up of 4.8 years, 35.3% of patients had OH at some point. OH was not significantly associated with the composite outcome (HR: 1.11, 95% CI: 0.80-1.54). Allocation to the intervention group in the NAILED trial was not associated with OH during follow-up (OR: 0.84, 95% CI: 0.62-1.13).

CONCLUSIONS

OH was not associated with an increased risk of CV events or death in this stroke/TIA population. Systematic titration of antihypertensive treatment did not increase the prevalence of OH compared to usual care. Thus, OH did not reduce the gains of antihypertensive treatment.

Orthostatic Blood Pressure Change, Dizziness, and Risk of Dementia in the ARIC Study

BACKGROUND

Abnormal orthostatic blood pressure (BP) regulation may result in cerebral hypoperfusion and brain ischemia and contribute to dementia. It may also manifest as early symptoms of the neurodegenerative process associated with dementia. The relationship between the magnitude and timing of orthostatic BP responses and dementia risk is not fully understood.

METHODS

We conducted a prospective cohort analysis of the associations of orthostatic BP changes and self-reported orthostatic dizziness with the risk of dementia in the Atherosclerosis Risk in Communities study (ARIC). We calculated changes in BP from the supine to the standing position at 5 measurements taken within 2 minutes after standing during the baseline visit (1987-1989). The primary outcome was adjudicated dementia ascertained through 2019.

RESULTS

Among 11 644 participants (mean [SD] age, 54.5 [5.7] years; 54.1% women; 25.9% Black), 2303 dementia cases were identified during a median follow-up of 25.9 years. Large decreases in systolic BP from the supine to standing position measured at the first 2 measurements ≈30 and 50 seconds after standing, but not afterward, were associated with orthostatic dizziness and a higher risk of dementia. Comparing a decrease in systolic BP of ≤-20 or >-20 to -10 mm Hg to stable systolic BP (>-10 to 10 mm Hg) at the first measurement, the adjusted hazard ratios were 1.22 (95% CI, 1.01-1.47) and 1.10 (95% CI, 0.97-1.25), respectively.

CONCLUSIONS

Abnormal orthostatic BP regulation, especially abrupt drops in BP within the first minute, might be early risk markers for the development of dementia. Transient early orthostatic hypotension warrants more attention in clinical settings.

Association between Parkinson's disease and the risk of adverse cardiovascular events: a systematic review and meta-analysis

Background

This review aims to examine the association of Parkinson's disease (PD) with the increased risk of cardiovascular events.

Methods

PubMed, Embase, CENTRAL, and Scopus databases were electronically searched for papers published up to 5 May 2023. Studies reporting the association between PD and the subsequent risks of stroke, myocardial infarction (MI), and cardiovascular mortality were included.

Results

Sixteen studies were included in this review. The clinical data of 101,712 PD patients were compared with that of the control group of 204,901 patients without PD in the included studies. Meta-analysis showed that PD patients had an increased risk of stroke compared with patients without PD (odds ratio (OR): 1.49; 95% confidence interval (CI): 1.30, 1.72; I2 = 76%). The pooled analysis demonstrated no significant increase in the risk of MI (OR: 1.16; 95% CI: 0.85, 1.59; I2 = 82%) and cardiovascular mortality (OR: 1.20; 95% CI: 0.93, 1.54; I2 = 65%) in PD patients. However, data from cohort studies indicated a possibility of higher risk of MI (OR: 1.36; 95% CI: 1.01, 1.84; I2 = 80%) and cardiovascular mortality (OR: 1.22; 95% CI: 1.00, 1.60; I2 = 62%) in patients with PD.

Conclusion

Patients with PD may have an increased risk of stroke as compared with the age- and gender-matched general population. While our results show that PD does not increase the overall risk of MI and cardiovascular mortality, analysis of cohort studies alone demonstrated that these risks may be higher in patients with PD. The current evidence is of very low quality. Further prospective cohort studies from different countries that would account for important cardiovascular risk factors are needed to improve the current evidence.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, PROSPERO (CRD42023421924).

Prospective association of occupational and leisure-time physical activity with orthostatic blood pressure changes in older adults

Orthostatic hypotension (OH) is common in older people. We examined the influence of self-reported occupational-related physical activity (PA) and leisure-time physical exercise (PE) on orthostatic response in a sample of older people over a 2 year period. Supine and orthostatic systolic blood pressure (sBP), diastolic blood pressure (dBP), and mean blood pressure (mBP) were assessed in response to Active Stand (AS) test in 205 older subjects (> 60 years old) at baseline and 2-year follow-up. OH was found in 24 subjects (11.71%) at baseline and 20 subjects (9.76%) after 2 years, with a significant degree of variability in the occurrence of OH after 2 years. Twenty-two subjects who had OH at baseline were free of it after 2 years, two subjects had persistent OH at baseline and after 2 years. After 2 years, adults with occupational PA showed no significant decrease of blood pressure in response to AS test, while lack of undertaking an occupation-related PA was significantly related with a greater decrease in sBP and mBP in response to AS testing in the 1st min. Occupation-related PA and leisure-time-related PE were related to an increase in the response of BP on AS in change between baseline and after 2 years. High between-subjects variance in OH over 2 years was noted. Occupations that involved continuous physical activity and leisure-time physical exercise in middle age were both protective for BP decline on orthostatic stress test within 2 years.

Predictors of Conversion to Dementia in Patients With Mild Cognitive Impairment: The Role of Low Body Temperature

Background

Subjects with mild cognitive impairment (MCI) can progress to dementia. Studies have shown that neuropsychological tests, biological or radiological markers individually or in combination have helped to determine the risk of conversion from MCI to dementia. These techniques are complex and expensive, and clinical risk factors were not considered in these studies. This study examined demographic, lifestyle and clinical factors including low body temperature that may play a role in the conversion of MCI to dementia in elderly patients.

Methods

In this retrospective study, a chart review was conducted on patients aged 61 to 103 years who were seen at the University of Alberta Hospital. Information on onset of MCI and demographic, social, and lifestyle factors, family history of dementia and clinical factors, and current medications at baseline was collected from patient charts on an electronic database. The conversion from MCI to dementia within 5.5 years was also determined. Logistic regression analysis was conducted to identify the baseline factors associated with conversion from MCI to dementia.

Results

The prevalence of MCI at baseline was 25.6% (335/1,330). During the 5.5 years follow-up period, 43% (143/335) of the subjects converted to dementia from MCI. The factors that were significantly associated with conversion from MCI to dementia were family history of dementia (odds ratio (OR): 2.78, 95% confidence interval (CI): 1.56 - 4.95, P = 0.001), Montreal cognitive assessment (MoCA) score (OR: 0.91, 95% CI: 0.85 - 0.97, P = 0.01), and low body temperature (below 36 °C) (OR: 10.01, 95% CI: 3.59 - 27.88, P < 0.001).

Conclusion

In addition to family history of dementia and MoCA, low body temperature was shown to be associated with the conversion from MCI to dementia. This study would help clinicians to identify patients with MCI who are at highest risk of conversion to dementia.

Stroke in Parkinson's disease: a review of epidemiological studies and potential pathophysiological mechanisms

Parkinson's disease (PD) is the fastest growing neurological disorder and one of the leading neurological causes of disability worldwide following stroke. An overall aging global population, as well as general changes in lifestyle associated with mass industrialization in the last century, may be linked to both increased incidence rates of PD and an increase in cumulative cardiovascular risk. Recent epidemiological studies show an increased risk of stroke, post-stroke complications, and subclinical ischemic insults in PD. PD patients have a host of characteristics that might contribute to increasing the risk of developing ischemic stroke including motor impairment, dysautonomia, and sleep disorders. This increases the urgency to study the interplay between PD and other neurological disorders, and their combined effect on mortality, morbidity, and quality of life. In this review, we provide a comprehensive overview of the studied etiological factors and pathological processes involved in PD, specifically with regard to their relationship to stroke. We hope that this review offers an insight into the relationship between PD and ischemic stroke and motivates further studies in this regard.

Blood pressure reduction cut-points for orthostatic hypotension in stroke survivors using a sit-up test: a multicentre cross-sectional study

OBJECTIVE

The sit-up test is used to assess orthostatic hypotension in stroke survivors who cannot stand independently without using a tilt table. However, no study has identified the optimal cut-points for orthostatic hypotension using the test. Therefore, this study aimed to examine the decrease in SBP and DBP during the sit-up test to detect orthostatic hypotension in individuals with stroke.

METHODS

Thirty-eight individuals with stroke, recruited from three convalescent rehabilitation hospitals, underwent the sit-up and head-up tilt tests. Systolic and diastolic orthostatic hypotension was defined as a decrease of at least 20 and 10 mmHg in the SBP and DBP, respectively, during the head-up tilt test. The receiver operator characteristic curve with the Youden Index was used to identify the optimal cut-points.

RESULTS

Eight and three participants showed systolic and diastolic orthostatic hypotension, respectively. The optimal cut-points for orthostatic hypotension using the sit-up test were a decrease of 10 mmHg in SBP [sensitivity = 87.5% (95% confidence interval: 47.4-99.7), specificity = 96.7% (82.8-99.9)] and 5 mmHg in DBP [sensitivity = 100.0% (29.2-100.0), specificity = 88.6% (73.3-96.8)].

CONCLUSION

Compared with the conventional cut-points, smaller cut-points of a decrease in SBP and DBP may be better to identify orthostatic hypotension in individuals with stroke using the sit-up test. The findings of this study may provide valuable information for the clinical application of the sit-up test.

Nomogram for Prediction of Postoperative Delirium after Deep Brain Stimulation of Subthalamic Nucleus in Parkinson’s Disease under General Anesthesia

Introduction. Postoperative delirium can increase cognitive impairment and mortality in patients with Parkinson’s disease. The purpose of this study was to develop and internally validate a clinical prediction model of delirium after deep brain stimulation of the subthalamic nucleus in Parkinson’s disease under general anesthesia. Methods. We conducted a retrospective observational cohort study on the data of 240 patients with Parkinson’s disease who underwent deep brain stimulation of the subthalamic nucleus under general anesthesia. Demographic characteristics, clinical evaluation, imaging data, laboratory data, and surgical anesthesia information were collected. Multivariate logistic regression was used to develop the prediction model for postoperative delirium. Results. A total of 159 patients were included in the cohort, of which 38 (23.90%) had postoperative delirium. Smoking (OR 4.51, 95% CI 1.56–13.02, $p<0.01$ ) was the most important risk factor; other independent predictors were orthostatic hypotension (OR 3.42, 95% CI 0.90–13.06, $p=0.07$ ), inhibitors of type-B monoamine oxidase (OR 3.07, 95% CI 1.17–8.04, $p=0.02$ ), preoperative MRI with silent brain ischemia or infarction (OR 2.36, 95% CI 0.90–6.14, $p=0.08$ ), Hamilton anxiety scale score (OR 2.12, 95% CI 1.28–3.50, $p<0.01$ ), and apolipoprotein E level in plasma (OR 1.48, 95% CI 0.95–2.29, $p=0.08$ ). The area under the receiver operating characteristic curve (AUC) was 0.76 (95% CI 0.66–0.86). A nomogram was established and showed good calibration and clinical predictive capacity. After bootstrap for internal verification, the AUC was 0.74 (95% CI 0.66–0.83). Conclusion. This study provides evidence for the independent inducing factors of delirium after deep brain stimulation of the subthalamic nucleus in Parkinson’s disease under general anesthesia. By predicting the development of delirium, our model may identify high-risk groups that can benefit from early or preventive intervention.

Orthostatic Hypotension in Hypertensive Adults: Harry Goldblatt Award for Early Career Investigators 2021

Orthostatic hypotension affects roughly 10% of individuals with hypertension and is associated with several adverse health outcomes, including dementia, cardiovascular disease, stroke, and death. Among adults with hypertension, orthostatic hypotension has also been shown to predict patterns of blood pressure dysregulation that may not be appreciated in the office setting, including nocturnal nondipping. Individuals with uncontrolled hypertension are at particular risk of orthostatic hypotension and may meet diagnostic criteria for the condition with a smaller relative reduction in blood pressure compared with normotensive individuals. Antihypertensive medications are commonly de-prescribed to address orthostatic hypotension; however, this approach may worsen supine or seated hypertension, which may be an important driver of adverse events in this population. There is significant variability between guidelines for the diagnosis of orthostatic hypotension with regards to timing and position of blood pressure measurements. Clinically relevant orthostatic hypotension may be missed when standing measurements are delayed or when taken after a seated rather than supine position. The treatment of orthostatic hypotension in patients with hypertension poses a significant management challenge for clinicians; however, recent evidence suggests that intensive blood pressure control may reduce the risk of orthostatic hypotension. A detailed characterization of blood pressure variability is essential to tailoring a treatment plan and can be accomplished using both in-office and out-of-office monitoring.

Combined association of triglyceride-glucose index and systolic blood pressure with all-cause and cardiovascular mortality among the general population

Background

The combined association of triglyceride-glucose (TyG) index and different systolic blood pressure (SBP) levels with all-cause and cardiovascular mortality among the general population remains unclear.

Methods

In this study, 6245 individuals were from the National Health and Nutrition Examination Survey (1999–2002). The study endpoints were all-cause and cardiovascular mortality. Multivariate Cox proportional hazards regression models were used to explore the combined association of TyG index and different SBP levels with all-cause and cardiovascular mortality.

Results

During a mean follow-up period of 66.8 months, a total of 284 all-cause deaths (331/100000 person-years) and 61 cardiovascular deaths (66/100000 person-years) were recorded. Multivariate Cox regression analysis revealed that the combination of low TyG index and low SBP (< 120 mmHg and < 130 mmHg) was associated with a reduced risk of all-cause and cardiovascular mortality than others. However, survival benefit was not observed in the combined group with the low TyG index and SBP < 140 mmHg. Furthermore, the mortality rate in the combined group of low TyG index and low SBP gradually increased with the elevation of SBP level.

Conclusion

The combination of low TyG index and low SBP (< 120 mmHg and < 130 mmHg) was associated with a lower risk of all-cause and cardiovascular mortality. However, no survival benefit was observed in the combined group of low TyG index and SBP < 140 mmHg.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03678-z.

Association of general and abdominal adiposity with postural changes in systolic blood pressure: results from the NAKO pretest and MetScan studies

The association between anthropometric measurements and postural changes in systolic blood pressure (SBP) has not been frequently reported. This study aimed to investigate the association of body mass index (BMI) and waist circumference (WC) with postural changes in SBP in two German cross-sectional studies. Data were derived from 506 participants of the population-based German National Cohort (NAKO) pretest and from 511 participants of the convenience sample-based MetScan studies. Linear regression models were used to estimate the association between BMI and WC with the difference between standing and sitting SBP (dSBP). Odds ratios (ORs) for an increase (dSBP > 10 mmHg) or decrease (dSBP ≤ -10 mmHg) in dSBP were calculated using logistic regression. The results were pooled by meta-analysis using an inverse variance model. In pooled analysis, a 5 kg/m² higher BMI was associated with a 1.46 mmHg (95% confidence interval (CI) 0.98-1.94) higher dSBP, while a 5 cm higher WC was associated with a 0.51 mmHg (95% CI 0.32-0.69) higher dSBP. BMI or WC were associated with a higher odds of an increase in dSBP (adjusted OR, 1.71; 95% CI 1.36-2.14 per 5 kg/m² higher BMI and 1.22; 95% CI 1.05-1.40 per 5 cm higher WC) but with a reduced odds of a decline in dSBP (adjusted OR, 0.67; 95% CI 0.44-1.00 per 5 kg/m² higher BMI and 0.84; 95% CI 0.72-0.99 per 5 cm higher WC). The associations between WC and dSBP were no longer statistically significant after BMI adjustments. In conclusion, higher BMI and higher WC were associated with higher postural increases in SBP; however, WC was not related to postural changes in SBP once adjusted for BMI.

Sex Differences in the Association Between Metabolic Dysregulation and Cognitive Aging: The Health and Retirement Study

BACKGROUND

Dysregulation of some metabolic factors increases the risk of dementia. It remains unclear if overall metabolic dysregulation, or only certain components, contribute to cognitive aging and if these associations are sex specific.

METHODS

Data from the 2006-2016 waves of the Health and Retirement Study (HRS) was used to analyze 7 103 participants aged 65 and older at baseline (58% women). We created a metabolic-dysregulation risk score (MDRS) composed of blood pressure/hypertension status, glycosylated hemoglobin (HbA1c)/diabetes status, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and waist circumference, and assessed cognitive trajectories from repeated measures of the HRS-Telephone Interview for Cognitive Status (HRS-TICS) over 10 years of follow-up. Linear mixed-effects models estimated associations between MDRS or individual metabolic factors (biomarkers) with mean and change in HRS-TICS scores and assessed sex-modification of these associations.

RESULTS

Participants with higher MDRSs had lower mean HRS-TICS scores, but there were no statistically significant differences in rate of decline. Sex stratification showed this association was present for women only. MDRS biomarkers revealed heterogeneity in the strength and direction of associations with HRS-TICS. Lower HRS-TICS levels were associated with hypertension, higher HbA1c/diabetes, and lower HDL-C and TC, whereas faster rate of cognitive decline was associated with hypertension, higher HbA1c/diabetes, and higher TC. Participants with higher HbA1c/diabetes presented worse cognitive trajectories. Sex differences indicated that women with higher HbA1c/diabetes to have lower HRS-TICS levels, whereas hypertensive males presented better cognitive trajectory.

CONCLUSIONS

Our results demonstrate that metabolic dysregulation is more strongly associated with cognition in women compared with men, though sex differences vary by individual biomarker.

New horizons in the ageing autonomic nervous system: orthostatic hypotension and supine hypertension

Blood pressure regulation is an automatic, moment-by-moment buffering of the blood pressure in response to physiological changes such as orthostasis, exercise and haemorrhage. This finely orchestrated reflex is called the baroreflex. It is a regulated arc of afferent, central and efferent arms. Multiple physiological changes occur with ageing that can disrupt this reflex, making blood pressure regulation less effective. In addition, multiple changes can occur with ageing-related diseases such as neurodegeneration, atherosclerosis, deconditioning and polypharmacy. These changes commonly result in orthostatic hypotension, hypertension or both, and are consistently associated with multiple adverse outcomes. In this article, we discuss the healthy baroreflex, and physiological and pathophysiological reasons for impaired baroreflex function in older people. We discuss why the common clinical manifestations of orthostatic hypotension and concomitant supine hypertension occur, and strategies for balancing these conflicting priorities. Finally, we discuss strategies for treating them, outlining our practice alongside consensus and expert guidance.

Diagnosis and treatment of orthostatic hypotension

Orthostatic hypotension is an unusually large decrease in blood pressure on standing that increases the risk of adverse outcomes even when asymptomatic. Improvements in haemodynamic profiling with continuous blood pressure measurements have uncovered four major subtypes: initial orthostatic hypotension, delayed blood pressure recovery, classic orthostatic hypotension, and delayed orthostatic hypotension. Clinical presentations are varied and range from cognitive slowing with hypotensive unawareness or unexplained falls to classic presyncope and syncope. Establishing whether symptoms are due to orthostatic hypotension requires careful history taking, a thorough physical examination, and supine and upright blood pressure measurements. Management and prognosis vary according to the underlying cause, with the main distinction being whether orthostatic hypotension is neurogenic or non-neurogenic. Neurogenic orthostatic hypotension might be the earliest clinical manifestation of Parkinson's disease or related synucleinopathies, and often coincides with supine hypertension. The emerging variety of clinical presentations advocates a stepwise, individualised, and primarily non-pharmacological approach to the management of orthostatic hypotension. Such an approach could include the cessation of blood pressure lowering drugs, adoption of lifestyle measures (eg, counterpressure manoeuvres), and treatment with pharmacological agents in selected cases.

Comparison of supine and seated orthostatic hypotension assessments and their association with falls and orthostatic symptoms

BACKGROUND

Orthostatic hypotension (OH) based on a change from seated-to-standing blood pressure (BP) is often used interchangeably with supine-to-standing BP.

METHODS

The Study to Understand Fall Reduction and Vitamin D in You (STURDY) was a randomized trial of vitamin D3 supplementation and fall in adults aged ≥70 years at high risk of falls. OH was defined as a drop in systolic or diastolic BP of at least 20 or 10 mmHg, measured at pre-randomization, 3-, 12-, and 24-month visits with each of 2 protocols: seated-to-standing and supine-to-standing. Participants were asked about orthostatic symptoms, and falls were ascertained via daily fall calendar, ad hoc reporting, and scheduled interviews.

RESULTS

Among 534 participants with 993 paired supine and seated assessments (mean age 76 ± 5 years, 42% women, 18% Black), mean baseline BP was 130 ± 19/68 ± 11 mmHg; 62% had a history of high BP or hypertension. Mean BP increased 3.5 (SE, 0.4)/2.6 (SE, 0.2) mmHg from sitting to standing, but decreased with supine to standing (mean change: -3.7 [SE, 0.5]/-0.8 [SE, 0.3] mmHg; P-value < 0.001). OH was detected in 2.1% (SE, 0.5) of seated versus 15.0% (SE, 1.4) of supine assessments (P < 0.001). While supine and seated OH were not associated with falls (HR: 1.55 [0.95, 2.52] vs 0.69 [0.30, 1.58]), supine systolic OH was associated with higher fall risk (HR: 1.77 [1.02, 3.05]). Supine OH was associated with self-reported fainting, blacking out, seeing spots and room spinning in the prior month (P-values < 0.03), while sitting OH was not associated with any symptoms (P-values ≥ 0.40).

CONCLUSION

Supine OH was more frequent, associated with orthostatic symptoms, and potentially more predictive of falls than seated OH.

Association Between Blood Pressure Variability With Dementia and Cognitive Impairment: A Systematic Review and Meta-Analysis

[Figure: see text].

Correlation of orthostatic hypotension with extracranial carotid and intracranial cerebral arteries atherosclerosis in patients with acute ischemic stroke under cerebral angiography

OBJECTIVE

The clinical management of patients with acute ischemic stroke (AIS) is complicated by orthostatic hypotension, which might have close relationship with the atherosclerosis of cerebral arteries. The primary objectives were to evaluate the relationship of orthostatic hypotension with extracranial carotid arteries atherosclerosis (ECAS) and intracranial atherosclerosis (ICAS) in AIS patients.

METHODS

This study was a prospective cohort analysis of consecutive AIS patients under cerebrovascular angiography. A total of 289 patients were included. orthostatic hypotension was defined as a systolic BP decline ≥20 mmHg or a diastolic BP decline ≥10 mmHg within 3 min of standing. Univariate and multivariate analysis were performed to investigate the association of the clinical variables with orthostatic hypotension.

RESULTS

Orthostatic hypotension was identified in 80 (27.7%) of all patients. ECAS (≥70%) and ICAS (≥50%) was found in 39 (13.5%) and 71 (24.6%) respectively. In multivariate analysis, only diabetes mellitus (odds ratio = 2.00, 95% confidence interval, 1.12-3.58, P = 0.019) and ECAS (odds ratio = 1.97, 95% confidence interval, 1.54-2.51, P < 0.001) were independent risk factors for orthostatic hypotension.

CONCLUSIONS

Orthostatic hypotension is a relatively common finding among patients with AIS. AIS patients should be screened for orthostatic hypotension, especially combined with severe ECAS and diabetes mellitus.

Relationships between subendocardial perfusion impairment, arterial stiffness and orthostatic hypotension in hospitalized elderly individuals

BACKGROUND

Orthostatic hypotension is an independent risk factor for cardiovascular morbidity and mortality. Arterial stiffness has been shown to be a pathophysiological mechanism linking orthostatic hypotension and increased cardiovascular risk. This study aims to evaluate the relationship between arterial stiffness, orthostatic hypotension and subendocardial viability ratio (SEVR) and moreover to identify the main predictors of orthostatic hypotension, carotid-femoral pulse wave velocity (PWV-cf) and SEVR.

METHODS

Seventy-five patients were enrolled (mean age 82.95 ± 6.45) in Verona's AOUI Geriatric ward. They underwent blood pressure, heart rate, body weight measurements and also comorbidity, arterial stiffness (PWV-cf measured by applanation tonometry), SEVR and biochemical indexes.

RESULTS

Prevalence of orthostatic hypotension was 46.6%. Even after adjustment for age, sex, glomerular filtration rate and mean arterial pressure, SEVR values corrected for arterial oxygen and haemoglobin content were statistically lower in orthostatic hypotension patients (P = 0.05) and PWV-cf values were statistically higher in orthostatic hypotension individuals (P = 0.042). In a binary logistic regression, PWV-cf was the only significant predictor of orthostatic hypotension (odds ratio 1.123; P = 0.039; confidence interval = 1.006--1.17).In a backward logistic regression model sex, creatinine clearance and orthostatic hypotension were significant predictors of SEVR corrected for O2 content. Mean arterial pressure, creatinine clearance and orthostatic hypotension were significant predictors of PWV-cf.

CONCLUSION

This study shows that orthostatic hypotension is related to increased arterial stiffness, confirming its higher prevalence in elderly patients. Orthostatic hypotension was also associated with reduced values of corrected SEVR, showing a relevant consequence of orthostatic hypotension on subendocardial perfusion impairment.

From Normal Cognition to Cognitive Impairment and Dementia: Impact of Orthostatic Hypotension

Supplemental Digital Content is available in the text.

The role of orthostatic hypotension (OH) in the continuum of cognitive aging remains to be clarified. We sought to investigate the associations of OH with dementia, cognitive impairment, no dementia (CIND), and CIND progression to dementia in older adults while considering orthostatic symptoms. This population-based cohort study included 2532 baseline (2001–2004) dementia-free participants (age ≥60 years; 62.6% women) in the SNAC-K (Swedish National Study on Aging and Care in Kungsholmen) who were regularly examined over 12 years. We further divided the participants into a baseline CIND-free cohort and a CIND cohort. OH was defined as a decrease by ≥20/10 mm Hg in systolic/diastolic blood pressure upon standing and further divided into asymptomatic and symptomatic OH. Dementia was diagnosed following the international criteria. CIND was defined as scoring ≥1.5 SDs below age group-specific means in ≥1 cognitive domain. Data were analyzed with flexible parametric survival models, controlling for confounding factors. Of the 2532 participants, 615 were defined with OH at baseline, and 322 were diagnosed with dementia during the entire follow-up period. OH was associated with an adjusted hazard ratio of 1.40 for dementia (95% CI, 1.10–1.76), 1.15 (0.94–1.40) for CIND, and 1.54 (1.05–2.25) for CIND progression to dementia. The associations of dementia and CIND progression to dementia with asymptomatic OH were similar to overall OH, whereas symptomatic OH was only associated with CIND progression to dementia. Our study suggests that OH, even asymptomatic OH, is associated with increased risk of dementia and accelerated progression from CIND to dementia in older adults.

Orthostatic hypotension: a marker of blood pressure variability and arterial stiffness: a cross-sectional study on an elderly population: the 3-City study

BACKGROUND

Orthostatic hypotension, blood pressure (BP) variability, and arterial stiffness are three markers of cardiovascular risk beyond the average BP. However, the relationships between these three parameters are not well known.

AIM

To examine the relationships between orthostatic hypotension, BP variability, and arterial stiffness.

METHODS AND RESULTS

In the Three-City study, a sample of 1151 elderly participants (mean age = 80 ± 3 years) was screened for orthostatic hypotension, undertook home BP and pulse wave velocity (PWV) measurements. We performed logistic regression analyses to look at the associations between orthostatic hypotension and both day-to-day (D-to-D) BP variability quartiles and PWV quartiles. Orthostatic hypotension was detected in 210 participants who were more likely to be hypertensive, exhibit higher BP variability and have increased arterial stiffness. In the multivariate logistic regression analysis, the frequency of orthostatic hypotension increased by 20% with every quartile of D-to-D SBP variability and by 20% with every quartile of PWV. PWV and D-to-D BP variability were not associated. In stratified analysis, the use of beta-blocker changes these relationships: orthostatic hypotension was not associated to PWV anymore but its association with D-to-D SBP variability was apparently stronger.

CONCLUSION

In this large sample of elderly individuals, orthostatic hypotension was independently associated with both BP variability and PWV. BP variability being more indicative of a baroreflex dysfunction and PWV being a marker of vascular ageing, these two components would participate to the orthostatic hypotension mechanisms.

Comparison of Dizziness Factors for Mild Traumatic Brain Injury Patients with and without Dizziness: A Factor Analysis and Propensity Score Model Study

Traumatic brain injury (TBI) causes major socioeconomic problems worldwide. In the United States, nearly three-quarters of patients with TBI have mild TBI (mTBI). 32% of these patients may develop dizziness. In this study, we analyzed the factor structure of the traditional Chinese version of the DHI and evaluate the differences in DHI factors between dizziness and nondizziness groups. In total, 315 patients with mTBI, comprising 158 with self-reported dizziness and 157 without dizziness, were recruited from three hospitals. The responses for Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Epworth Sleepiness Scale (ESS), and Pittsburgh Sleep Quality Index (PSQI) demonstrated between-group differences. The Chinese DHI had internal validity and had four factors that differed from the English version (3 aspects). The group effects for the physical subscale remained significantly different even after adjustments in the propensity score model. For the Chinese version, two of four factors remained significantly different in the effects between self-reported dizziness and nondizziness groups. The factors of our Chinese DHI differed from those of the original English version of DHI. After adjustments using the propensity score model, the physical subscale demonstrated significant differences between the self-reported dizziness and nondizziness groups. Only two factors from our Chinese DHI were significantly different; moreover, it contained only three physical, five functional, and three emotional items.

Plasma Concentrations of Magnesium and Risk of Dementia: A General Population Study of 102 648 Individuals

BACKGROUND

Low and high concentrations of plasma magnesium are associated with increased risk of future all-cause dementia; however, the underlying reasons remain elusive. The magnesium ion is an important electrolyte serving as a cofactor in many enzymatic processes in the human organism. Magnesium affects both neuronal and vascular functions. We investigated the associations of plasma concentrations of magnesium associate with common subtypes of dementia as Alzheimer dementia and non-Alzheimer dementia, and potential pathways by which magnesium may affect risk of dementia.

METHODS

Plasma concentrations of magnesium were measured in 102 648 individuals from the Copenhagen General Population Study. Cox regression and natural effects mediation analyses evaluated associations with either Alzheimer dementia or non-Alzheimer dementia.

RESULTS

Multifactorially adjusted hazard ratios for non-Alzheimer dementia were 1.50(95% confidence interval (CI):1.21-1.87) for the lowest and 1.34(1.07-1.69) for the highest vs the fourth quintile (reference) of plasma magnesium concentrations. Diabetes, cumulated smoking, stroke, and systolic blood pressure mediated 10.4%(3.1-22.8%), 6.8%(1.2-14.0%), 1.3%(0.1-3.6%), and 1.0%(0.2-2.6%), respectively, in the lowest quintile, whereas stroke mediated 3.2%(0.4-11.9%) in the highest quintile. No associations were observed for Alzheimer dementia.

CONCLUSIONS

Low and high plasma magnesium concentrations were associated with high risk of vascular-related non-Alzheimer dementia, with the lowest risk observed at a concentration of 2.07 mg/dL (0.85 mmol/L). No association was observed for Alzheimer dementia. Mediation analysis suggested that diabetes may be in the causal pathway between low plasma magnesium concentrations and high risk of non-Alzheimer dementia, while cumulated smoking, stroke, and systolic blood pressure played minor mediating roles.

Perioperative Neurological Evaluation and Management to Lower the Risk of Acute Stroke in Patients Undergoing Noncardiac, Nonneurological Surgery: A Scientific Statement From the American Heart Association/American Stroke Association

Perioperative stroke is a potentially devastating complication in patients undergoing noncardiac, nonneurological surgery. This scientific statement summarizes established risk factors for perioperative stroke, preoperative and intraoperative strategies to mitigate the risk of stroke, suggestions for postoperative assessments, and treatment approaches for minimizing permanent neurological dysfunction in patients who experience a perioperative stroke. The first section focuses on preoperative optimization, including the role of preoperative carotid revascularization in patients with high-grade carotid stenosis and delaying surgery in patients with recent strokes. The second section reviews intraoperative strategies to reduce the risk of stroke, focusing on blood pressure control, perioperative goal-directed therapy, blood transfusion, and anesthetic technique. Finally, this statement presents strategies for the evaluation and treatment of patients with suspected postoperative strokes and, in particular, highlights the value of rapid recognition of strokes and the early use of intravenous thrombolysis and mechanical embolectomy in appropriate patients.

Systemic and cerebral circulatory adjustment within the first 60 s after active standing: An integrative physiological view

Transient cardiovascular and cerebrovascular responses within the first minute of active standing provide the means to assess autonomic, cardiovascular and cerebrovascular regulation using a real-world everyday stimulus. Traditionally, these responses have been used to detect autonomic dysfunction, and to identify the hemodynamic correlates of patient symptoms and attributable causes of (pre)syncope and falls. This review addresses the physiology of systemic and cerebrovascular adjustment within the first 60 s after active standing. Mechanical factors induced by standing up cause a temporal mismatch between cardiac output and vascular conductance which leads to an initial blood pressure drops with a nadir around 10 s. The arterial baroreflex counteracts these initial blood pressure drops, but needs 2-3 s to be initiated with a maximal effect occurring at 10 s after standing while, in parallel, cerebral autoregulation buffers these changes within 10 s to maintain adequate cerebral perfusion. Interestingly, both the magnitude of the initial drop and these compensatory mechanisms are thought to be quite well-preserved in healthy aging. It is hoped that the present review serves as a reference for future pathophysiological investigations and epidemiological studies. Further experimental research is needed to unravel the causal mechanisms underlying the emergence of symptoms and relationship with aging and adverse outcomes in variants of orthostatic hypotension.

Neuroprosthetic baroreflex controls haemodynamics after spinal cord injury

Spinal cord injury (SCI) induces haemodynamic instability that threatens survival^1-3, impairs neurological recovery^4,5, increases the risk of cardiovascular disease^6,7, and reduces quality of life^8,9. Haemodynamic instability in this context is due to the interruption of supraspinal efferent commands to sympathetic circuits located in the spinal cord¹⁰, which prevents the natural baroreflex from controlling these circuits to adjust peripheral vascular resistance. Epidural electrical stimulation (EES) of the spinal cord has been shown to compensate for interrupted supraspinal commands to motor circuits below the injury¹¹, and restored walking after paralysis¹². Here, we leveraged these concepts to develop EES protocols that restored haemodynamic stability after SCI. We established a preclinical model that enabled us to dissect the topology and dynamics of the sympathetic circuits, and to understand how EES can engage these circuits. We incorporated these spatial and temporal features into stimulation protocols to conceive a clinical-grade biomimetic haemodynamic regulator that operates in a closed loop. This 'neuroprosthetic baroreflex' controlled haemodynamics for extended periods of time in rodents, non-human primates and humans, after both acute and chronic SCI. We will now conduct clinical trials to turn the neuroprosthetic baroreflex into a commonly available therapy for people with SCI.

Relationship between sarcopenia and orthostatic hypotension

BACKGROUND

The relationship between sarcopenia and orthostatic hypotension (OH) is unclear.

OBJECTIVES

The aim of the present study was to investigate associations between sarcopenia/sarcopenia severity and OH.

DESIGN

A total of 511 patients attending a geriatric outpatient clinic were included. OH was defined as a decrease in systolic and/or diastolic blood pressure of ≥ 20 mmHg and/or ≥ 10 mmHg, respectively, when one transitions from the supine to an upright position. OH was measured by the Head-up Tilt Table test at 1, 3 and 5 min (OH1, OH3 and OH5, respectively). Sarcopenia and its severity were defined according to the revised European consensus on definition and diagnosis.

RESULTS

The mean age of the sample was 75.40 ± 7.35 years, and 69.9% were female. The prevalence of probable sarcopenia, sarcopenia and severe sarcopenia was 42.2%, 6.06% and 11.1%, respectively. After adjustment for all covariates, systolic OH1, OH1 and systolic OH5 were statistically significantly different between severe sarcopenia and the robust group (odds ratio [OR]: 3.26, confidence interval [CI] 0.98-10.84; P = 0.05 for systolic OH1; OR 4.31, CI 1.31-14.15; P = 0.016 for OH1; OR 4.09, CI 1.01-16.55; P = 0.048 for systolic OH5). Only systolic OH1 was statistically different between the sarcopenia and severe sarcopenia groups (OR 2.64, CI 1.87-8.73; P = 0.012). OH1 and OH5 were statistically significant different between severe sarcopenia and probable sarcopenia groups (P < 0.05); there was no relationship between the robust group and probable sarcopenia (P > 0.05).

CONCLUSIONS

There is a close relationship between sarcopenia and severe sarcopenia and OH in older adults. Therefore, when a healthcare practitioner is evaluating an older patient with sarcopenia, OH should also be evaluated, and vice versa.

Postural blood pressure changes in the elderly: orthostatic hypotension and hypertension

Objectives

Orthostatic hypotension is a well-known disorder, but orthostatic hypertension (OHT) still remains unclear in older adults. The aim of this study was to determine the comparison orthostatic hypotension with OHT according to fall risk and geriatric assessment parameters.

Methods

A total of 741 patients who were admitted to the geriatric clinic and underwent comprehensive geriatric assessment were reviewed. Orthostatic blood pressure changes were measured by head-up-tilt Table test within the first three minutes. Orthostatic hypotension was defined as 20 or 10-mmHg drop in systolic and/or diastolic blood pressure from supine to standing position. OHT was defined as an increase in systolic blood pressure of 10 mmHg or more while the patient was standing up from the supine position.

Results

The mean age was 75 ± 8 and 65. About 65% of all participants were female. The rate of orthostatic hypotension and OHT was 17.3 and 7.2%, respectively. The falls and dementia were more frequent, and the Instrumental Activities of Daily Living (IADL) score was lower in orthostatic hypotension group than in OHT and control groups (P < 0.05). These variables were similar between OHT and control groups (P > 0.05). The rates of falls [odds ratio (OR) = 2.02; 95% confidence interval (CI), (0.94–4.33); P = 0.044] and dementia [OR = 2.65; 95% CI, (1.08–6.48); P = 0.032] in orthostatic hypotension group were still higher than in OHT group, even after adjusting for age, sex, estimated glomerular filtration rate and drugs.

Conclusion

Orthostatic hypotension may be more significant in terms of falls, dementia and impaired IADLs scores in older adults than in OHT and control groups. It seems that OHT may be of no clinical importance in geriatric practice.

Addressing Orthostatic Hypotension in Heart Failure: Pathophysiology, Clinical Implications and Perspectives

Heart failure (HF)is a condition at high risk for orthostatic hypotension (OH)given the large proportion of patients at an advanced age and high burden of comorbidities contributing to OH, as well as a high prevalence of medications with neurovascular and volume modulating properties. Early identification of OH in HF seems to be crucial as OH can have an impact on patient symptoms, activity level and independence, be a marker of specific pathophysiological changes or be an indicator of need for personalized treatment. OH might contribute significantly to bad enough prognosis in HF, as, besides a risk of falls and cognitive decline, it was found to be associated with cardiovascular morbidity and mortality. In this review, we aimed to incentivize the routine use of orthostatic testing in HF, as well as stimulate future research in this field, which could lead to significant advances in the treatment and outcomes.

Intensive control of hypertension and risk of Alzheimer's dementia in older adults with depression

OBJECTIVES

Intensive control of hypertension has been reported to decrease risk of cognitive decline. However, the effect of this in older adults with hypertension and comorbid depression is not well understood. We aim to identify whether intensive control of systolic blood pressure (BP) is associated with reduced risk of Alzheimer's dementia (AD) in a clinical population.

METHODS

Using data from the National Alzheimer's Coordinating Center, we conducted survival analyses in older adults with normal cognition at baseline and treated hypertension. We also examined those with comorbid depression, to determine if intensive control of systolic BP (≤120 mmHg) was associated with reduced risk of AD.

RESULTS

In all older adults with treated hypertension (n = 4505), 298 (6.6%) developed AD during a median follow-up duration of 4.2 years. In the comorbid depression subgroup (n = 1327), 152 (11.5%) developed AD. Intensive control of systolic BP was not significantly associated with reduced risk of AD in the overall sample (HR 1.13, 95%, 0.79-1.64). However, in the comorbid depression subgroup, intensive control of systolic BP (≤120 mmHg) was associated with increased risk of AD (HR 1.49, 95%, 1.03-2.15) compared to standard control (121-139 mmHg).

CONCLUSIONS

In a clinical population of older adults with hypertension and comorbid depression, we found that an intensive systolic BP target of ≤120 mmHg was associated with increased risk of AD. While these findings are preliminary, they suggest that a more cautious approach to hypertension treatment may be warranted in this vulnerable subgroup.

Orthostatic hypotension, dizziness, neurology outcomes, and death in older adults

OBJECTIVE

To test the hypothesis that orthostatic hypotension (OH) might cause cerebral hypoperfusion and injury, we examined the longitudinal relationship between OH or orthostatic symptoms and incident neurologic outcomes in a community population of older adults.

METHODS

Cardiovascular Health Study participants (≥65 years) without dementia or stroke had blood pressure (BP) measured after lying down for 20 minutes and after standing 3 for minutes. Participants reported dizziness immediately upon standing and any dizziness in the past 2 weeks. OH was defined as a drop in standing systolic/diastolic BP ≥20/≥10 mm Hg. We determined the association between OH or dizziness with (1) MRI brain findings (ventricular size, white matter hyperintensities, brain infarcts) using linear or logistic regression, (2) cognitive function (baseline and over time) using generalized estimating equations, and (3) prospective adjudicated events (dementia, stroke, death) using Cox models. Models were adjusted for demographic characteristics and OH risk factors. We used multiple imputation to account for missing OH or dizziness (n = 534).

RESULTS

Prior to imputation, there were 5,007 participants (mean age 72.7 ± 5.5 years, 57.6% women, 10.9% Black, 16% with OH). OH was modestly associated with death (hazard ratio [HR] 1.11; 95% confidence interval 1.02-1.20), but not MRI findings, cognition, dementia, or stroke. In contrast, dizziness upon standing was associated with lower baseline cognition (β = -1.20; -1.94 to -0.47), incident dementia (HR 1.32; 1.04-1.62), incident stroke (HR 1.22; 1.06-1.41), and death (HR 1.13; 1.06-1.21). Similarly, dizziness over the past 2 weeks was associated with higher white matter grade (β = 0.16; 0.03-0.30), brain infarcts (OR 1.31; 1.06-1.63), lower baseline cognition (β = -1.18; -2.01 to -0.34), and death (HR 1.13; 1.04-1.22).

CONCLUSIONS

Dizziness was more consistently associated with neurologic outcomes than OH 3 minutes after standing. Delayed OH assessments may miss pathologic information related to cerebral injury.

Systolic blood pressure postural changes variability is associated with greater dementia risk

OBJECTIVE

To determine whether orthostatic hypotension (OHYPO) and visit-to-visit blood pressure (BP) postural changes variability are associated with incident dementia.

METHODS

We studied 2,131 older adults from the Health, Aging, and Body Composition cohort study. Orthostatic BP was repeatedly assessed over a 5-year baseline period. OHYPO was defined as a fall ≥15 mm Hg in systolic or ≥7 mm Hg in diastolic BP after standing from a sitting position for one-third or more of the visits. Systolic OHYPO and diastolic OHYPO were also examined separately. BP postural changes variability over time was evaluated with several indicators, including SD and coefficient of variation (CV). Incident dementia was determined over 12 years after the baseline period by dementia medication use, ≥1.5 SD decline in Modified Mini-Mental State Examination score, or hospitalization records.

RESULTS

Of 2,131 participants (mean age 73 years, 53% female, 39% Black), 309 (14.5%) had OHYPO, 192 (9.0%) had systolic OHYPO, 132 (6.2%) had diastolic OHYPO, and 462 (21.7%) developed dementia. After adjustment for demographics, seated systolic BP (SBP), antihypertensive drugs, cerebrovascular disease, diabetes mellitus, depressive symptoms, smoking, alcohol, body mass index, and presence of 1 or 2 APOE ε4 alleles, systolic OHYPO was associated with greater dementia risk (adjusted hazard ratio [HR] 1.37, 95% confidence interval [CI] 1.01-1.88), unlike diastolic OHYPO and OHYPO. SBP postural changes variability was also associated with higher dementia risk (highest tertile of variability [CV]: adjusted HR 1.35, 95% CI 1.06-1.71).

CONCLUSION

Systolic OHYPO and visit-to-visit SBP postural changes variability were associated with greater dementia risk. Our findings raise the question of potential preventive interventions to control orthostatic SBP and its fluctuations.

Hypertension and Drug Adherence in the Elderly

Hypertension is highly prevalent after the age of 65 years affecting more than 60% of individuals in developed countries. Today, there is sufficient evidence from clinical trials that treating elderly subjects with hypertension with antihypertensive medications has a positive benefit/risk ratio even in very elderly patients (>80 years). In recent years, partial or total non-adherence has been recognized as major issues in the long-term management of hypertension in all age categories. However, whether non-adherence is more frequent in hypertensive patients older than 65 years or not is still a matter of debate and the common belief is that adherence is lower in older than in younger patients. Are clinical data supporting this belief? In this brief review, we discuss the topic of drug adherence in elderly in the context of the medical treatment of hypertension. Studies show that drug adherence is actually better in patients aged 65 to 80 years when compared to younger hypertensive patients (<50 years). However, in very old patients (>80 years) the prevalence of non-adherence does increase. In this patients' group, there are specific risk factors for non-adherence such as cognitive ability, depression, and health believes, in addition to classical risk factors for non-adherence. One important aspect in the elderly is the prescription of potentially inappropriate medications that will interfere with the adherence to necessary treatments. In this context, an interesting new concept was developed few years ago, i.e., the process of deprescribing. Thus, today, in addition to conventional guidelines recommendations (use of single pill combinations, individualization of treatments), the evaluation of cognitive abilities, the regular assessment of potentially inappropriate medications, and the process of deprescribing appear to be three new additional steps to improve drug adherence in the elderly and thereby ameliorate the global management of hypertension.

Diverse cognitive impairment after spinal cord injury is associated with orthostatic hypotension symptom burden

This study: 1) compared cognitive functioning between individuals with chronic (>1 year) spinal cord injury (SCI) and non-injured controls and, 2) assessed associations between symptoms of autonomic dysreflexia and orthostatic hypotension with cognitive functioning in SCI participants with a history of unstable blood pressure (BP). Thirty-two individuals with SCI (C4-L2, American Spinal Injury Association Impairment Scale A-D) and thirty age, sex-matched non-injured controls participated in this study. Participants completed a motor-free neuropsychological test battery assessing 1) memory, 2) attention/concentration/psychomotor speed and, 3) executive function. Nineteen participants with SCI who had injuries ≥T6 and a history of unstable BP also completed the Autonomic Dysfunction Following Spinal Cord Injury (ADFSCI) questionnaire. Cognitive function was significantly lower in people with SCI across measures of memory and executive function compared to non-injured controls. Significant, moderate-to-large associations were observed between cumulative (frequency x severity) orthostatic hypotension and total BP instability symptoms scores, with measures of attention/concentration/psychomotor speed and executive function. These data demonstrate a 10 - 65% reduced performance across specific realms of cognitive functioning in individuals with SCI relative to non-injured controls. Furthermore, cumulative subjective scores for symptoms of unstable BP were associated with diverse cognitive deficits. These findings, in individuals without co-occurring traumatic brain injury, imply cardiovascular dysregulation plays a role in cognitive deficits observed in this population.